Dynamic stop

ABSTRACT

A dynamic stop for an operator-less railway transportation system consisting of an arm positioned between the tracks of the transportation system and pivotably mounted so that it does not interfere with the passage of the cars of the railway transportation system when not in use, but may be rotated up so that an absorbent stop plate mounted thereon will contact an absorbent bumper mounted on the front of the car which it is desired to stop. The dynamic stop may be mounted on a reciprocating device to further absorb the energy of contact.

DYNAMIC sToP FIELD OF THE INVENTION The invention relates generally to the selective stopping of cars in an operator-less, railway type transportation system and, more specifically, to the stopping of operator-less, remotely controlled cars in a transportation system such as is disclosed in commonly assigned US. Pat. Nos. 3,621,790, 3,626,859, and 3,650,216.

BACKGROUND OF THE INVENTION I To meet the demands of some transportation systems, it is necessary or desirable to use a large number of small carriers, or cars rather than a few large carriers, or trucks. This is particularly true when the freight to be carried by the transporation system must be sent to a large number of different destinations, but promptness is required, so that it is feasible to accumulate to any great extent different loads going to a common destination. Such systems, moreover, may be extremely heavily. traffickedvas wh ere they are used for baggage transportation in a major airport or mail transporation in a large post office. In such situations, it is necessary that mechanism be provided to permit rapid, selective stopping of the cars in the transporation system. This stopping may be required, for instance, before switching points, in idle car storage areas, and before car elevators and turn-tables. Such a mechanism is disclosed in general terms, but not claimed, in commonly assigned U.S. Pat. No. 3,626,859.

SUMMARY OF THE INVENTION The cars of an operator-less, railway-type transportation system may be readily and selectively stopped-by means of an arm positioned between the tracks of the transportation system and pivotably mounted so that it does not interfere with the passage of the cars when not in use, but may be rotated up so that an absorbent stop plate mounted thereon willcontact an absorbent bumper mounted on the front of the cars. In a further refinement of thepresent invention, the stop may be mounted on a reciprocating device, the actuation of which on contact with the car further absorbs the energy of the contact.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a dynamic stop constructed in accordance with the present invention showing the dynamic stop in the raised position.

FIG. 2 is a side view of the dynamic stop shown in FIG. l in the raised position.

FIG. 3 is a side view of the dynamic stop shown in FIG. l in the lowered position.

DETAILED DESCRIPTION OFTHE PREFERRED EMBODIMENT In the preferred embodiment of this invention, two absorbent stop plates l are mounted on stop arms 11. The stop arms 11 are pivotably attached to pivot arms l2, spring arms 13, and shock absorbers 14, each of which is in turn pivotably attached to the connecting pivot shaft l5. The connecting pivot'shaft l5 is pivotably mounted in lateral supports 26, which are fixedly 6 or the trade'way support structure in a manner not shown. As may be seen most clearly in FIGS. 2 and 3,v

this arrangement permits the stop plates 10 to be rotated clockwise about the pivot 16 by the impact of absorbent car bumper 17. However, the rotation is resisted by the shock absorbers 14 and, to some extent, by the die springs 18 mounted on the spring arms 13, thereby absorbing the energy of the contact. The die springs 18 serve also to return the stop arms ll to an upright position and the shock absrobers 14 to their normal condition once the pressure of the car against the stop plates 10 is removed. It should be noted that this arrangement permits the stop arms 1l to function independently which is an advantage over the dynamic stop disclosed and claimed in copending application, Ser. No. 309,373, tiled Nov. 24, 1972. This advantage particularly suits the dynamic stop disclosed herein for use on curved portions of the track. However, even on straight portions of the track it is important because the play allowed between the rails and the wheels can allow the car to cock slightly on the track.

The pivot arms 12 are also pivotably attached to cam arms 19, which are in turn pivotably attached to linkage 20, which connects the cam arms 19 and causes them to operate in unison. Linkage 20 is connected to the piston 21 of dual-action fluid cylinder 22, which is pivotably mounted in the center ofthe trackway on cylinder bracket 23. This mechanism permits the stop plate 10 and the upper portions of stop arms 1l, spring arms 13, and shock absorbers 14 to be rotated down out of the way of approaching cars. Roller bearings 24 are mounted on the bottoms of the cam arms 19, and these rollers bearings run along cam tracks 2S when the fluid cylinder 22 is actuated. The actuation of the fluid cylinder 22 may be controlled by any appropriate means for example, the mechanism disclosed in commonly assigned U.S. Pat. No. 3,626,859.

It will be readily appreciated by those skilled in the art that various modifications in form and detail can be made inthe above described embodiment without departing from the scope of the inventive concept. For example, the pivoting portion of the mechanism may be mounted on a reciprocating mechanism which would then reciprocate the two arms as a unit. For this reason the scope of the invention must be measured by the appended claims and not by the preferred embodiment disclosed herein.

What is claimed is:

l. A dynamic stop for selectively stopping the cars of a unit transporation system having a plurality of cars which travel along tracks, said dynamic stop comprismg:

l. a pivot shaft adapted to be pivotably mounted adjacent to the tracks of a unit transportation system in a direction generally perpendicular to the direction of movement of the cars on the tracks;

2. a pivot arm mounted for pivoting around said pivot shaft;

3. a stop arm pivotably connected to said pivot arm about an axis parallel to said pivot shaft at a point thereon remote from said pivot shaft;

4. A shock absorber operatively connecting said stop arm to said pivot arm so as to resist pivoting movement of said stop arm with respect to said pivot arm in the direction of movement of the cars on the tracks;

A dual-action fluid cylinder having a piston which is pivotably connected to said pivot arm at a point thereon remote from said pivot shaft for causing said pivot arm to pivot about said pivot shaft to shift said stop arm between operative and inoperative positions, said fluid cylinder being adapted to be pivotably mounted adjacent to the tracks of a unit transportation system about an axis generally parallel to said pivot shaft.

2. A dynamic stop as claimed in claim l in which the piston of said dual-action fluid cylinder is connected to said pivot arm by means of a cam arm which acts as a linkage therebetween, said cam arm being pivotably connected .to said pivot arm at a point thereon remote from said pivot shaft and the piston of said dual-action fluid cylinder being pivotably connected to said cam arm at a point thereon remote from said pivot arm.

3. A dynamic stop as claimed in claim 2 and further comprising:

l. A cam track adapted to be mounted adjacent to the tracks of a unit transportation system and 2. A roller bearing rotatably mounted on said cam arm in a position to cooperate with said cam track during actuation of said dual-action fluid cylinder.

4. A dynamic stop as claimed in claim 3 and comprising at least two sub-assemblies each one of which comprises a pivot arm, a stop arm, and a shock absorber connected together in the manner previously recited, whereby each sub-assembly acts separately, thereby compensating for slight variations in the direction of motion of the ears of the unit transportation system.

5. A dynamic stop as claimed in claim 1 and comprising at least two sub-assemblies cach one of which comprises a pivot arm, a stop arm, and a shock absorber connected together in the manner previously recited, whereby each sub-assembly acts separately, thereby compensating for slight variations in the direction of motion of the cars in the unit transportation system.

6. A dynamic stop as claimed in claim 1 and further comprising means for biasing said stop arm with respect to said pivot arm in the direction opposite to the movement of the cars on the track, whereby said stop arm will have a tendency to return to an initial position after one of the cars has been stopped by it.

UNITED STATES PATIENT OFFICE CERTIFICATE 0F CRRECTION Patent No. 3, 8.28, 688 Dated August 13, 1974 Invent0r(s) Bernard Bradbury It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In The Specification:

Column 1, line `15 comma should be after cars line 17 "transporation" should read transportation line 19 after "is" (second occurrence) not should be inserted line Z3 transporation (second occurrence) should read transportation line Z6 "transporation" should read transportation line 35 "readily" should read rapidly line 42 no space between "the present" Column 2, line 1 "tradeway" should read trackway line 14 after "independently", a comma should be inserted line '51 "transporation" should read transportation line 63 "A" should read a Column 3, line 1 "A" should read a Signed and sealed this 12th day of November 1974.

(SEAL) Attest:

McCOY GIBSON JR. C. MARSHALL DANN Attestlng Officer Commissioner of Patents 1 FORM Po-1o5o (1o-69) USCOMM-DC 60376-P69 u.s. GOVERNMENT PRINTING orFlcE: Ins o--sss-asa, 

1. A dynamic stop for selectively stopping the cars of a unit transporation system having a plurality of cars which travel along tracks, said dynamic stop comprising:
 1. a pivot shaft adapted to be pivotably mounted adjacent to the tracks of a unit transportation system in a direction generally perpendicular to the direction of movement of the cars on the tracks;
 2. a pivot arm mounted for pivoting around said pivot shaft;
 3. a stop arm pivotably connected to said pivot arm about an axis parallel to said pivot shaft at a point thereon remote from said pivot shaft;
 2. a pivot arm mounted for pivoting around said pivot shaft;
 2. A dynamic stop as claimed in claim 1 in which the piston of said dual-action fluid cylinder is connected to said pivot arm by means of a cam arm which acts as a linkage therebetween, said cam arm being pIvotably connected to said pivot arm at a point thereon remote from said pivot shaft and the piston of said dual-action fluid cylinder being pivotably connected to said cam arm at a point thereon remote from said pivot arm.
 2. A roller bearing rotatably mounted on said cam arm in a position to cooperate with said cam track during actuation of said dual-action fluid cylinder.
 3. A dynamic stop as claimed in claim 2 and further comprising:
 3. a stop arm pivotably connected to said pivot arm about an axis parallel to said pivot shaft at a point thereon remote from said pivot shaft;
 4. A shock absorber operatively connecting said stop arm to said pivot arm so as to resist pivoting movement of said stop arm with respect to said pivot arm in the direction of movement of the cars on the tracks;
 4. A shock absorber operatively connecting said stop arm to said pivot arm so as to resist pivoting movement of said stop arm with respect to said pivot arm in the direction of movement of the cars on the tracks;
 4. A dynamic stop as claimed in claim 3 and comprising at least two sub-assemblies each one of which comprises a pivot arm, a stop arm, and a shock absorber connected together in the manner previously recited, whereby each sub-assembly acts separately, thereby compensating for slight variations in the direction of motion of the cars of the unit transportation system.
 5. A dynamic stop as claimed in claim 1 and comprising at least two sub-assemblies each one of which comprises a pivot arm, a stop arm, and a shock absorber connected together in the manner previously recited, whereby each sub-assembly acts separately, thereby compensating for slight variations in the direction of motion of the cars in the unit transportation system.
 5. A dual-action fluid cylinder having a piston which is pivotably connected to said pivot arm at a point thereon remote from said pivot shaft for causing said pivot arm to pivot about said pivot shaft to shift said stop arm between operative and inoperative positions, said fluid cylinder being adapted to be pivotably mounted adjacent to the tracks of a unit transportation system about an axis generally parallel to said pivot shaft.
 5. A dual-action fluid cylinder having a piston which is pivotably connected to said pivot arm at a point thereon remote from said pivot shaft for causing said pivot arm to pivot about said pivot shaft to shift said stop arm between operative and inoperative positions, said fluid cylinder being adapted to be pivotably mounted adjacent to the tracks of a unit transportation system about an axis generally parallel to said pivot shaft.
 6. A dynamic stop as claimed in claim 1 and further comprising means for biasing said stop arm with respect to said pivot arm in the direction opposite to the movement of the cars on the track, whereby said stop arm will have a tendency to return to an initial position after one of the cars has been stopped by it. 